Guide to SFP+ Transceivers

Since March 1999, the Ethernet industry has been working on providing solutions to these problems by increasing the speed of Ethernet from 1 to 10 gigabits per second. For enterprise LAN applications, 10 Gigabit Ethernet enables network managers to scale their Ethernet networks from 10 Mbps to 10,000 Mbps, while leveraging their investments in Ethernet as they increase their network performance. Meanwhile, the newest module standard, namely the enhanced small form-factor pluggable (SFP+) transceiver , has been developed to meet the increasing usage and demand for higher-performance servers, storage and interconnects in the 10 Gigabit Ethernet world.

What Is the SFP+

The small form-factor pluggable plus (SFP+) can be referred to as an enhanced version of the SFP that supports data rates up to 16 Gbit/s. The SFP+ specification was first published on May 9, 2006, and version 4.1 published on July 6, 2009. SFP+ supports 8Gbit/s Fiber Channel, 10 Gigabit Ethernet and Optical Transport Network standard OTU2. It is a popular industry format supported by many network component vendors. The SFP+ product family includes cages, connectors, and copper cable assemblies. The SFP+ transceiver modules are specified for 8Gbps/10Gbps/16Gbps Fiber Channel and 10-Gigabit Ethernet applications.

Advantages of SFP+ Transceivers

SFP+ transceiver comes with various outstanding advantages. SFP+ covers various data rates for different communication standards like Ethernet, SONET (OC-192), SDH (STM-64) or 10G Fiber Channel and any other interfaces with a data rate up to 16 Gbps. It is with more compact size and measurement than former X2, Xenpak and XFP, which enables SFP+ suitable for installations with higher port density. In addition, SFP+ takes the advantage of lower power consumption for less than 1W, like 455883-B21 compatible 10GBASE-SR SFP+ transceiver shown in the following picture. SFP+ transceivers are with managed digital optical monitoring and superior high temperature performance. Therefore, it is a cost effective way to connect a single network device to a wide variety of fiber cable distances and types using a SFP+ transceiver module.

Applications of SFP + Transceivers

SFP+ transceivers are designed to use together with small form factor connectors and offer high speed and physical compactness, providing instant fiber connectivity for your networking gear. They are available for copper and for all common fiber modes, wavelengths and data rates and allow network operators to connect different interface types to the same network equipment, via an SFP+ port. To take advantage of this flexibility and to save money, more and more network equipment are being designed with SFP/SFP+ ports. Several industrial acknowledged standards for SFP+ have been made for 10Gpbs networks, including 10Gbase-SR which defines the SFP+ transceiver working with OM3 10G multimode fiber at 30 to 300 meters range, 10Gbase-LR which defines the SFP-10G-LR transceiver working with single mode fiber at 10km range, and so on.

To conclude, 10 Gigabit Ethernet has become the technology of choice for enterprise, metropolitan, and wide area networks. In terms of physical media, the 10G SFP+ transceiver can support distances to 300 meters on multimode fiber and 40 km or more on single mode fiber. Fiberstore is a leading supplier of SFP+ transceivers. We have a large selection of SFP+ transceivers in stock, such us SFP+ MM 300m, SFP+ 10km, SFP+ 40km, SFP+ 80km, CWDM SFP+, DWDM SFP+, BiDi SFP+, etc. All of our SFP+ transceivers are tested in-house prior to shipping to ensure that they will arrive in perfect physical and working condition.

FAQ About OM4 Fiber

The explosion in demand for bandwidth in enterprise networks is driving an urgent need for higher Ethernet network speeds. Increasingly, these higher bandwidth system requirements have dictated a need to transition from cost-effective multi-mode systems to more costly single-mode systems. Until OM4 was formally specified, many 40G and 100G applications would have had to make the leap to single-mode system solutions. OM4 effectively provides an additional layer of performance that supports these applications at longer distances.

What is “OM4” fiber?

OM4 is a laser-optimized, high bandwidth 50 micrometer multimode fiber. In August of 2009, TIA/EIA approved and released 492AAAD, which defines the performance criteria for this grade of optical fiber. It can be used to enhance the system cost benefits enabled by 850 nm VCSELs for the earlier 1 G and 10 Gb/s applications as well as the 40 and 100 Gb/s systems. For example, Fibestore's Push-Pull MPO patch cable is manufactured using laser-optimized, 50/125, OM4 multimode cable, and supports speeds up to 100GbE. OM4 fiber can support Ethernet, Fibre Channel, and OIF applications, allowing extended reach upwards of 550 meters at 10 Gb/s for ultra long building backbones and medium length campus backbones. OM4 fiber is also especially well suited for shorter reach data center and high performance computing applications.

What are the standards that define the use of OM4 fiber?

There are a number of standards under development that will define the use of OM4 fiber for high-speed transmission. Within the TIA, work is progressing on TIA-492AAAD, which will contain the OM4 fiber performance specifications. Similarly, IEC is working in parallel to adopt equivalent specs that is documented in the international fiber standard IEC 60793-2-10.

What bandwidth does the standard specify for OM4 fiber?

As of this writing, there is general agreement among the standards committees that OM4 has a significantly higher bandwidth (EMB of 4700 MHz-km with VCSEL launch at 850 nm) than OM3. It is also backward compatible with applications calling for OFL bandwidth of at least 500 MHz-km at 1300 nm (e.g. FDDI, IEEE 100BASE-FX, 1000BASE-LX, 10GBASE-LX4, and 10GBASE-LRM). There was some discussion and debate within the standards groups about a minimum OFL bandwidth requirement at 850 nm. It has been shown that fibers with higher OFL bandwidth can perform better with VCSELs that launch more power into outer modes. That is why the existing OM3 fiber standards require a minimum 1500 MHz-km OFL bandwidth at 850 nm.

What’s the difference between OM3 and OM4?

It is important to note that OM4 glass is not necessarily designed to be a replacement for OM3. Despite the relatively long-standing availability of OM4, there are no plans to obsolete OM3 fiber optic cabling. For most systems, OM3 glass is sufficient to cover the bandwidth needs at the distances of the current installation base. Most system requirements can still be reliably and cost effectively achieved with OM3, and this glass type will remain available for the foreseeable future. Despite the availability of OM4 glass, OM3 is quite capable of 40 and 100 Gb/s applications albeit at significantly shorter distances than OM4. For instance, Cisco QSFP-40G-CSR4 compatible transceiver from Fiberstore can reach 300m and 400m, respectively over OM3 and OM4 cables.

A variety of cable configurations are available utilizing the OM4 fiber for in-building and inter-building applications including the following types: distribution, breakout, interconnect, loose tube and industrial armored. All of Fiberstore’s OM4 cable assemblies are with high quality and competitive prices. They are assembled and 100% optically tested in the factory prior to shipment.

How Much Do You Know About 40G QSFP+ AOC

40 Gigabit Ethernet era is already upon us and makes a contribution to satisfying the increasing demands of higher throughputs and bandwidth. Existing and emerging network technologies are driving the need for high-density optical connectivity solutions to address the trends to optimized cable management and data center real estate usage. The 40G QSFP+ AOC (active optical cable) has been widely used in data center to achieve 40G interconnection. This article will introduce the 40G QSFP+ AOC in data center applications.

Development of AOC

Primarily, active optical cable (AOC) assemblies were invented to replace copper technology in data centers and high performance computing (HPC) applications. As we know, copper cable is heavy and bulky, making it difficult to physically manage the datacenter. And due to the nature of electrical signals, electromagnetic interference (EMI) limits copper’s performance and reliability. Though there are so many disadvantages of copper cable, at that time, it is the main stream while the idea of AOCs almost seems too good to be true. However, the advantages of AOC make the predecessors look obsolete and unsophisticated, and changes the limitation of copper cable as well as playing an important role in high speed data transmission. Nowadays, a variety of AOCs have been launched in the market, such as 10GbE SFP+ AOCs, 40Gbps QSFP+ AOCs and 120G CXP AOCs, for 10G, 40G and 100G applications.

What Is 40G QSFP+ AOC

40G AOC, is a type of active optical cable for 40GbE applications that is terminated with 40GBASE-QSFP+ on one end, while on the other end, in addition to QSFP+ connector, it can be terminated with SFP+ connector, LC, SC, FC, and ST connector etc. The 40G QSFP+ AOC is a parallel 40Gbps quad small form factor pluggable (QSFP+) active optical cable, which supplies higher port density and total system cost. The QSFP+ optical modules provide four full-duplex independent transmit and receive channels, each are able of 10Gbps operation 40Gbps aggregate bandwidth of at least 100m multimode fiber. Most DAC assemblies have one module on each end of the cable. But there is a special kind of DAC assembly which may have 3 or 4 modules on one end of the cable. For instance, Cisco QSFP-4X10G-AOC5M compatible QSFP+ to 4SFP+ breakout AOC from Fiberstore has a single QSFP+ module rated for 40-Gbps on one end and four SFP+ modules, each rated for 10-Gbps, on the other end.

40G QSFP+ AOC vs QSFP+ Optics

• Cost: 40G AOCs cost lower than SR4 modules and do not need to use together with extra fiber patch cables. For instance, Arista AOC-Q-Q-40G-10M compatible QSFP+ to QSFP+ active optical cables are suitable for very short distances and offer a very cost-effective way to establish a 40-gigabit link between QSFP ports of Arista switches within racks and across adjacent racks. Besides, when using 40G AOC, there are no cleanliness issues in optical connector and there is no need to do termination plug and test when troubleshooting, which can help user save more time and money.
• Insertion Loss & Return Loss: Under the same case of transmission distance, the repeatability and interchangeability performances of SR4 module interface are not good as 40G AOC. What’s more, when different fiber optic patch cables plug into the module, it will have the different insertion loss and return loss. Even for the same module, this issue is existed. Of course, the related metrics such as the testing eye pattern will have no significant changes so long as the variation in and conformed to the scope. In contrast, an AOC with good performance is more stable and has better swing performance than SR4 modules in this situation.

All in all, 40G QSFP+ AOC is highly recommended to use in data center interconnection. Apart from the 40G QSFP+ AOC, Fiberstore also supplies 10G SFP+ AOC, QSFP + AOC to 8 x LC and 120G CXP AOC, etc. All of them can meet the ever increasing need to cost-effectively deliver more bandwidth, and can be customized to meet different requirements.

Optical Fiber Loss Testing

Optical loss testing of multimode fiber can be affected by many variables, including fiber mismatch, the type and quality of the test reference cords and the launch conditions for launching light into the fiber under test. This article will look at how these different variables can affect the optical loss performance of a link under test.

Optical Loss Testing - Why It Is Important

Providing an accurate method for optical loss testing of multimode fiber is becoming a lot more important for higher data rate applications that place more stringent requirements on the maximum allowable loss for a channel between an optical transmitter and an optical receiver. The higher the data rate, the tighter the loss budget for a channel. The maximum allowable loss for a 10Gb/s Ethernet channel over OM3 multimode fiber is 2.6 dB. The maximum allowable loss for a 40 Gb/s and a 100 Gb/s Ethernet channel is 1.9 dB over OM3 fiber and 1.5 dB over OM4 fiber.

Factors That Affect The Accuracy of Optical Loss Testing

There are several major factors that can affect the testing accuracy for optical loss measurements. These include: 1.The type and quality of the “test reference cords”

The type and quality of the “test reference cord” is critical for accurate optical loss measurements in the field. The end-face geometry of the polished ferrule on the cord connector can have a significant effect on the test results and must meet precise parameters such as radius of curvature, apex and fiber protrusion.

2.Fiber mismatch between the test reference cords and the link under test

Fiber mismatches are the result of inherent fiber characteristics and are independent of the techniques used to join the two optical fibers. The intrinsic coupling loss due to fiber mismatch include core diameter differences, core/cladding concentricity error, numerical aperture differences.

3.The characteristics of light source and how light is coupled into the fiber

The launch conditions and how light is coupled into the fiber can have the greatest effect on optical loss measurements. For multimode fiber, different distributions of launch power (launch conditions) can result in different attenuation measurements.

Testing Tools

Fiber optic cable testing needs special tools and instruments. And they must be appropriate for the components or cable plants being tested. The following five kinds of fiber testing tools are needed for the testing work.

• OLTS—Optical loss test set (OLTS) with optical ratings matching the specifications of the installed system (fiber type and transmitter wavelength and type) and proper connector adapters. Power meter and source are also needed for testing transmitter and receiver power for the system testing.
• Reference test cable—This cable should be with proper sized fiber and connectors and compatible mating adapters of known good quality. And the connector loss is less than 0.5 dB.
• VFL—Visual fiber tracer or visual fault locator (VFL)
• Microscope—Connector inspection microscope with magnification of 100-200X, video microscopes recommended.
• Cleaning Materials—Cleaning materials intended specifically for the cleaning of fiber optic connectors, such as dry cleaning kits or lint free cleaning wipes and pure alcohol.

FiberStore offers a wide selection of fiber testers & tools to fit any fiber optic cable lineman or powerline worker jobs. We stock top high quality test equipment for the communications applications. In the fiber optic installation and maintenance works, Optical Power Meters, Fiber Light Sources, Fiber Scopes and OTDR are commonly used for fiber optic testing. And Splicing fiber tools, termination tool kits and cleaning tools, like strippers, cable cutters, splice protective sleeves help work easier. Besides, high quality fiber cables, such as Push-Pull MPO patch cable, push and pull cable, Push-Pull LC cable are also available for your choice. If you need any service, please contact us via sales@fs.com.

Guide to 40GBASE-SR4 QSFP+ Transceivers

Today’s enterprise data centers and networking environments are undergoing an infrastructure transformation, requiring higher speeds, greater scalability, and higher levels of performance and reliability to better meet the demands of business. As speed and performance needs increase, the 40GBASE-SR4 QSFP+ optical transceivers have become an integral part of overall system design. This article will give you a comprehensive introduction to 40GBASE-SR4 QSFP+ optical transceivers.

What Is 40GBASE-SR4 QSFP + Transceiver

40GBASE-SR4 is a fiber optic interface for multimode fiber of OM classes 3 and 4 with four parallel OM3 or OM4 fibers in both directions. “S” means short, indicating that it is an interface for short distances. The “R” denotes the type of interface with 64B/66B encoding and the numeral 4 indicates that the transmission is carried out over a ribbon fiber with four multimode fibers in every direction. Each lane has a 10 Gbit/s data rate. The 40GBASE-SR4 QSFP+ transceivers are hot-swappable, low-voltage digital diagnostic Ethernet optical transceivers that support high-speed serial links over multi-mode optical fiber at a signaling rate of 4×10 Gbps. They comply with QSFP+ mechanical, optical, and electrical specifications (SFF-8436). 40GBASE-SR4 QSFP+ modules usually use a parallel multimode fiber (MMF) link to achieve 40G. It offers 4 independent transmit and receive channels, each capable of 10G operation for an aggregate data rate of 40G over 100 meters of OM3 MMF or 150 meters of OM4 MMF. It primarily enables high-bandwidth 40G optical links over 12-fiber parallel fiber terminated with MPO/MTP multifiber female connectors.

Applications of 40GBASE-SR4 QSFP + Transceiver

40GBASE-SR transceivers are used in data centers to interconnect two Ethernet switches with 8 fiber parallel multimode fiber OM3/OM4 cables. The QSFP+ transceiver modules can be connected to both copper and optical cables. In the process of transmitting data, the 40GBASE-SR4 QSFP+ transceiver converts parallel electrical input signals into parallel optical signals by a 850nm vertical cavity surface emitting laser (VCSEL) array. All data signals are differential and the data rate can be up to 10 Gbps per channel. For example, Extreme 10319 compatible 40GBASE-SR4 QSFP+ transceiver from Fiberstore operates in 4-lanes at a wavelength of 850nm.

QSFP-40G-SR4 vs. QSFP-40G-CSR4

40GBASE-CSR4 QSFP modules extend the reach of the IEEE 40GBASE-SR4 interface to 300 and 400 meters on laser-optimized OM3 and OM4 multimode parallel fiber, respectively. Each 10-gigabit lane of this module is compliant to IEEE 10GBASE-SR specifications. This module can be used for native 40G optical links over 12-fiber parallel cables with MPO/MTP female connectors or in a 4x10G mode with parallel to duplex fiber breakout cables for connectivity to four 10GBASE-SR interfaces. Cisco compatible QSFP-40G-CSR4 transceiver from Fiberstore is optimized to guarantee interoperability over the complete specification range of 10GBASE-SR.

Fiberstore offers a wide range options of brand-compatible 40GBASE-SR4 QSFP+ transceivers. In order to ensure each transceiver with high-compatibility, we have a comprehensive and reliable test assured program for each optics. All these 40GBASE-SR4 QSFP+ transceivers will be tested in the original-brand switches to guarantees the high compatibility.